EcoSeed

A team of researchers from China and the US say bacteria that occur in wastewater can actually be used to produce energy needed in water desalination.

Researchers from the Penn State University and Tsinghua University in Beijing are working on “microbial fuel cells.” In this device, naturally occurring bacteria in the wastewater consume organic material, producing electricity.

The microbial desalination cell first cleans water by removing organic material from it. This process produces electricity which can then be used to desalinate water so that it can be safe for drinking.

Currently, it takes a lot of electricity to desalinate water, which is accomplished in many locations using a process called reverse osmosis, one that pushes water under high pressure through membranes that allow water to pass but not salt.

The researchers, however, admit that the system still has to be improved. In their tests, it took 200 milliliters of artificial wastewater containing acetic acid to desalinate just 3 milliliters of salty water. Another concern is that bacteria that run the cell might have a problem living in highly acidic environments, which happens in the cell as protons work their way from one electrode to another.

“This is not a practical system yet as it is not optimized, but it is proof of concept," Bruce Logan, Kappe professor of environmental engineering at Penn State, said.

The study was reported in a recent online issue of Environmental Science and Technology. It was supported by Saudi Arabia’s King Abdullah University of Science and Technology and the Ministry of Science and Technology of China.


- Katrice R. Jalbuena